A typical prior art intravenous butterfly needle "bn", as used for the insertion into blood vessels and similar passageways in the body to permit the infusion or withdrawal of sterile fluids or blood, is illustrated in FIGS. 1 and 2. The butterfly needle generally has a hollow needle or needle cannula "n", a cylindrical hub or housing "h" for the needle, and a wing-like extension "w" extending on each side thereof. The wings of the needle assembly provide a larger surface area to which adhesive tape can be secured. This assists the technician or nurse in affixing the needle to the patient during the infusion of fluids or medicants. The wings of the needle assembly may also be folded upwards around the hub to provide a gripping extension for the technician or nurse to use when attempting to insert the needle into the desired vein, artery or other passageway.
A problem with the butterfly needles as just described is that when the sharpened end of the needle is withdrawn from the vein or artery, it remains exposed and can be a source of great danger to the operator or to anyone who might be pricked or scratched by the exposed end of the needle. Needle injuries may result in the transmission of diseases such as hepatitis and HIV and may also lead to infection. One common solution available to the operator was to simply drop the needle and its holder into a trash receptacle. Another solution is to attempt to recap the needle with a safety cover immediately after use. This, however, may in itself cause injury if the operator should accidently stick themselves during the recapping process.